Building a chopper based on a rigid frame is not an original idea -- in fact, it is far from it. But incorporating all of the differences you want in a frame can lead to a very original design. You just have to be ready to cut, bend, weld, and cut some more. While it is not easy, it is fun; just ask Joe Martin of Martin Brothers in Duncanville, Texas, how much he enjoyed building this bike. The only plan for it was to be original, so nothing was off-limits as Martin and his guys worked on the project.
Everything for the bike would be done in-house, except the 113ci motor, which would be built by Bob McCaa of A.P.C. The all S&S mill would be polished to a jewel-like finish and the heads treated to some pretty innovative flow work, all in the interest of maximum performance. The Martin crew prepared a RevTech six-speed transmission with equally brilliant polishing and P.M. covers to ride behind the 113; they also planned a BDL open beltdrive and clutch to make the two polished jewels work in harmony. Knowing the powertrain was sorted out, Joe turned his attention to the frame for his new creation.
It started life as a Diamond Chassis rigid with pretty mild geometry, but Joe stretched it 10 inches in the downtubes and raked it to 40 degrees. A set of Diamond 5-degree trees hold 14-inch over 41mm tubes in wide glide legs that get some extra support from a custom Martin Brothers fork brace. Rolling the bike around was accomplished once the 21- and 18-inch P.M. Villain wheels were wrapped up in Metzeler rubber and slid in place.
Stopping is an all P.M. affair -- the rear benefiting from a driveside conversion. Once the roller was together, Joe started thinking about sheetmetal. He stopped when he realized the seat post was ruining his oil tank plans, so he cut it out and moved it behind the transmission mounting plate to make room for his ideas. First, a flat-bottom tank was built to flow from the trees all the way back to the wild, split rear fender, which is blended into the frame to look seamless.
Since they had taken all the time to relocate the seat post, Joe came up with an oil tank that used all the extra space. It starts at the top of the rear cylinder head and flows all the way past the rear splash-guard area. Realizing that he had given the bike a very radical profile, Joe felt some additional framework was necessary. A filler panel was added to the downtubes, just below the neck, and another in front of the lower motor mount. Then fins were added just for the fun of it. Martin Brothers bars were built to carry the P.M. hand controls, and the headlamp comes from Headwinds.
Before the Legends foot controls were installed, a special pair of sleeves was built for the fork tubes that add a point to them, just below the bottom tree. A taillight from Leo's Custom and a seat pan by Joe Martin rounded out those build. All that remained was ironing out a few details and paint. One of the details was where to put the throttle cable -- it was just flopping around to begin with. Joe grabbed a drill and put a hole in the tank near its mounting points and passed the cable through.
Problem solved. Time for paint.
The wild colors and graphics were done at Martin Brothers, with some special paint mixes by Toxic Tom at P.P.G. When the paints stopped flying and the clear set up, there was no doubt in Joe's mind that this was a special chopper. He had definitely achieved his vision of doing something just a little different!
| spec sheet |
| GENERAL |
| Owner: | Joe Martin |
| Year/Make: | '02/Chopper |
| Fabrication: | Martin Brothers |
| Assembly: | Martin Brothers |
| Build Time: | Three months |
| ENGINE |
| Size/Type: | 113 S&S |
| Cases: | S&S |
| Flywheels: | S&S |
| Rods: | S&S |
| Pistons: | S&S |
| Cylinders: | S&S |
| Heads: | S&S/A.P.C. |
| Cam: | S&S |
| Carb: | S&S |
| Ignition: | Crane |
| Pipes: | Martin Brothers |
| TRANSMISSION |
| Year/Type: | '02/RevTech |
| Case: | RevTech |
| Gears: | Six-speed |
| Clutch: | BDL |
| Primary Drive: | BDL |
| FRAME/SUSPENSION |
| Year/Type: | '02/Diamond Rigid |
| Rake: | 40 degrees |
| Stretch: | 10 inches |
| Swingarm: | Rigid |
| Rear Suspension: | As if |
| Forks: | 41 mm |
| Extension: | 14 inches |
| Triple Trees: | Diamond |
| WHEELS, TIRES, AND BRAKES |
| WHEELS |
| Front: | P.M. |
| Rear: | P.M. |
| TIRES |
| Front: | Metzeler |
| Rear: | 240 Metzeler |
| BRAKES |
| Front: | P.M. |
| Rear: | P.M. driveside |
| FINISH |
| Molding: | Bruce Hammond |
| Painter: | Joe Martin |
| Color: | Many |
| Graphics: | Many |
| Chrome Plating and Polishing: | Al's Plating |
| Powdercoating: | None |
| ACCESSORIES |
| Bars: | Martin |
| Risers: | Built-in |
| Hand Controls: | P.M. |
| Headlight: | Headwinds |
| Taillight: | Leo's |
| Gauges: | None |
| Electrical: | Martin |
| Fuel Tank(s): | Martin |
| Dash: | None |
| Oil Tank: | Martin |
| Front Fender: | None |
| Rear Fender: | Martin |
| Fender Struts: | Built-in |
| Pegs: | Legends |
| Foot Controls: | Legends |
| Seat: | Le Pera |